Boiling cooling system



Feb. 2, 1965 M. P. LATTERNER ETAL BOILING COOLING SYSTEM Filed Feb. 10,1964 Engine 2 Sheets-Sheet 1 (3|- M lg 1 PM Kip I b W J .J

NVENTORS M/chae/fi afferner' BY Th omas F Ro5ek Feb. 2, 1965 M. P.LATTERNER ETAL 3,168,030

BOILING COOLING SYSTEM Filed Feb. 10, 1964 2 Sheets-Sheet 2 f} 4INVENTORS M/O/IOE/P. L0 fern 8/ Y Thomas F. RO

d HTTORNEY United States Patent Ofilice 3,158fl8fi Patented Feb. 2, 19553,168,080 BGILING CGGLING SYSTEM Michael P. Latterner, Midland, andThomas Rozek,

Bay City, Mich., assignors toThe Dow Chemical Comparry, Midland, Mich, acorporation of Delaware Filed Feb. 10, 1964, Ser. No. 343,543 1 tliaim.(Cl. 123-41.26)

This invention relates to an improved boiling heat transfer system, andmore particularly to improved means for venting of non-condensible gasesfrom such a system.

In systems employing boiling cooling, a common problem exists.Non-condensible gaseous materials such as air, combustion gases, or thelike, must be bled from the cooling system periodically to insure properfunctioning of the system. In substantially all of the previouslyproposed methods to solve this problem, substantial quantities ofcoolant vapor are lost in the bleeding or venting process.

We have discovered an improved means for venting non-condensible gasesfrom boiling cooling systems, whereby loss of coolant is substantiallyminimized.

Objects and advantages of the present invention will become apparent inthe course of the following specification when read in light of theaccompanying drawings in which like numbering is used throughout and inwhich:

FIGURE 1 is a simplified schematic drawing illustrating a boilingcooling system;

FIGURE 2 is a plan view, partially in section, of the coolant storagetank shown in FIGURE 1;

FIGURE 3 is -a side elevation of the coolant storage tank taken alongline 3-3 of FIGURE 2, showing the tank at reduced coolant level; and

FIGURE 4 is a side elevation of the coolant storage tank taken alongline 44 of FIGURE 2, showing the tank at maximum coolant level.

In accordance with the present invention, a boiling cooling system foran internal combustion engine 113, comprising a cooling jacket integralwith said internal combustion engine and a condenser 11 connectedthereto, is provided with a coolant storage tank 12 communicating withsaid condenser 11 at the portion of said condenser 11 distant from saidengine it) by means of a suitable coolant inlet 14. The coolant storagetank 12 is provided with a coolant inlet 14, a bag vent 15, a tank vent16, and a collapsible bag 18.

Coolant inlet 14 is positioned in such a manner that coolant enters andleaves from the bottom portion of coolant storage tank 12, regardless ofthe vertical positional relationship of coolant storage tank 12 relativeto condenser 11. Thus, the location of coolant storage tank 12 may beabove condenser 11, as shown in FIG- URE 1, or may be level with orbelow condenser 11.

Bag vent 15 is usually a short tube-like communication means between theatmosphere and the interior of collapsible bag 18. Expanded volume ofcollapsible bag 13 is usually substantially the internal volume ofcoolant storage tank 12, but may be more or, when storage tank 12contains coolant under non-operating conditions, less than the internalvolume of coolant storage tank 12.

Tank vent 16 communicates between the atmosphere and the interior ofcoolant storage tank 12 and is provided with a two-position, open-shutvalve 19 actuated as by means of a float 20. Float 2i) and valve 19 arepreferably protected from contact with the collapsible bag 18 by meansof a barrier 22, such as a screen, thereby to freely allow the float tofollow the coolant level in storage tank 12. For simplicity, and toprevent confusion, barrier 22 is not shown in FIGURES 3 and 4.

Valve 19 is designed to open when float 20 is in the position whichcorresponds to the coolant level when the engine is not operating asillustrated in FIGURE 3, thereby establishing communication between theatmosphere and the interior of coolant storage tank 12. Valve 19 doesnot close, then, until float 20 is in the position corresponding to thecoolant level under start-up conditions.

In operation, when engine 10 is started, expansion drives coolantthrough condenser 11 and into coolant storage tank 12. A liquid trap 21may be employed on condenser 11, if desired, to insure a liquid seal atthe end of the condenser 11 nearest coolant storage tank 12. Valve 19remains open as the coolant level rises, thus expelling non-condensiblesto the atmosphere through tank vent 16. When the coolant reaches apre-determined level as illustrated by FIGURE 4, float 20 actuates valve19, causing valve 19 to close. Fluctuations in coolant level duringoperation are compensated for by the flow of air into or out ofcollapsible bag 18. As the coolant level falls, collapsible bag 18expands and as the coolant level rises, collapsible bag 18 collapses,thereby equalizing the pressure in coolant storage tank 12 with theatmosphere.

When the engine is shut off, the coolant level in coolant storage tank12 drops to its minimum height, which is never reached while the engineis operating. Float 21), following the level of coolant in storage tank12, actuates valve 19 and opens tank vent 16 to the atmosphere when apredetermined level is reached. This level is also below the minimumcoolant level during operation.

Non-condensible gases work their way to the coolant storage tank 12 andare vented to the atmosphere through tank vent 16 during the periodswhen valve 19 is in the open position. In this manner, the system isvented only during start up periods when the coolant is at temperatureswhich are low relative to normal operating temperatures, thus minimizingcoolant loss due to vaporization during venting.

Generally, metal would be the preferred material for fabrication ofcoolant storage tank 12, but any material which is substantially inertto the coolant employed and capable of withstanding temperaturesencountered in an ebullient cooling system may be satisfactorilyemployed.

Collapsible bag 18 is a bag fabricated of material (such as, forexample, high temperature resistant pliable rubber, plastics, or thelike) which is substantially impervious to air and the coolant employedin the system and is capable of withstanding normal temperaturesencountered in operation of the system.

Various modifications may be made in the present invention withoutdeparting from the spirit or scope thereof, and it is to be understoodthat we limit ourselves only as defined in the appended claim.

We claim:

In a boiling cooling system for an internal combustion engine, saidsystem comprising a condenser connected to a cooling jacket integralwith said internal combustion engine and containing coolant, theimprovement which comprises in combination a coolant storage tankcommunicating with said condenser by means of a coolant inlet, saidcoolant storage tank being provided with a bag vent, a tank vent, acollapsible bag within said tank, said collapsible bag connected to saidbag vent, said bag vent providing communication between the atmosphereand the interior of said collapsible bag, said tank vent having anopenshut valve attached thereto, said tank vent providing communicationbetween the interior of said coolant storage tank and the atmosphere,said valve having actuation means whereby said valve is opened when thecoolant level falls below a predetermined minimum and closes when thecoolant level reaches a predetermined maximum.

No references cited.

